Imaging optical system, image capturing device, and electronic device

ABSTRACT

An imaging optical system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element has positive refractive power in a paraxial region thereof. The second lens element has negative refractive power in a paraxial region thereof. Both of the third and fourth lens elements have refractive power. The fifth lens element with refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The sixth lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof. The imaging optical system has a total of six lens elements with refractive power.

RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 14/518,446 filed on Oct. 20, 2014, now approved and claims priorityto Taiwan Application Serial Number 103125977, filed on Jul. 30, 2014,which is incorporated by reference herein in its entirety.

BACKGROUND Technical Field

The present disclosure relates to an imaging optical system. Moreparticularly, the present disclosure relates to a compact imagingoptical system applicable to an electronic device.

Description of Related Art

As personal electronic products nowadays has been becoming more and morecompact, the internal components of the electronic products are alsorequired to be smaller in size than before. Except for the demand ofminiaturization, the advanced semiconductor manufacturing technologiesmaking the pixel size of sensors to be reduced have also urged compactoptical systems to evolve toward the field of higher megapixels. Inaddition, the popularity of smart phones and tablet personal computersalso significantly increases the requirements for high resolution andimage quality of present compact optical systems. Therefore, there isalso an increasing demand for compact optical systems featuring betterimage quality.

The conventional optical systems usually adopt more lens elements (ex.an optical system with six lens elements) to fulfill the demand ofhigher image quality. However, adopting more lens elements inevitablyincreases the difficulty in reducing the total track length thereof.Therefore, it is not favorable for the current market trends of beingcompact. It is critical to make a balance between obtaining high imagequality and keeping a compact size. Furthermore, the sensitivity of thesystem is also an important factor in the modern optical systems, sinceexcessively high sensitivity will result in difficulty in manufacturingand is not favorable for mass production.

To sum up, there is a need for an imaging optical system satisfying thedemand of compactness and is able to provide high image quality andsuitable sensitivity.

SUMMARY

According to one aspect of the present disclosure, an imaging opticalsystem including, in order from an object side to an image side: a firstlens element having positive refractive power in a paraxial regionthereof; a second lens element having negative refractive power in aparaxial region thereof; a third lens element having refractive power; afourth lens element having refractive power; a fifth lens element withrefractive power having an object-side surface being concave in aparaxial region thereof and an image-side surface being convex in aparaxial region thereof; wherein both of the object-side surface and theimage-side surface of the fifth lens element are aspheric; and a sixthlens element with positive refractive power in a paraxial region thereofhaving an object-side surface being convex in a paraxial region thereofand an image-side surface being concave in a paraxial region thereof;wherein both of the object-side surface and the image-side surface ofthe sixth lens element are aspheric, and the image-side surface of thesixth lens element has at least one inflection point; wherein theimaging optical system has a total of six lens elements with refractivepower; wherein a focal length of the imaging optical system is f, acurvature radius of the image-side surface of the fourth lens element isR8, an axial distance between the fourth lens element and the fifth lenselement is T45, a central thickness of the fifth lens element is CT5,and the following conditions are satisfied:

−0.50<f/R8; and

0.30<T45/CT5.

According to another aspect of the present disclosure, an imagingoptical system including, in order from an object side to an image side:a first lens element having positive refractive power in a paraxialregion thereof; a second lens element having refractive power; a thirdlens element having refractive power; wherein both of an object-sidesurface and an image-side surface of the third lens element areaspheric; a fourth lens element having refractive power; wherein both ofan object-side surface and an image-side surface of the fourth lenselement are aspheric; a fifth lens element with refractive power havingan object-side surface being concave in a paraxial region thereof and animage-side surface being convex in a paraxial region thereof; whereinboth of the object-side surface and the image-side surface of the fifthlens element are aspheric; and a sixth lens element with positiverefractive power in a paraxial region thereof having an object-sidesurface being convex in a paraxial region thereof and an image-sidesurface being concave in a paraxial region thereof; wherein both of theobject-side surface and the image-side surface of the sixth lens elementare aspheric, and the image-side surface of the sixth lens element hasat least one inflection point; wherein the imaging optical system has atotal of six lens elements with refractive power; wherein a focal lengthof the imaging optical system is f, a curvature radius of the image-sidesurface of the fourth lens element is R8, and the following condition issatisfied:

−0.20<f/R8.

According to yet another aspect of the present disclosure, an imagecapturing device includes the imaging optical system according to theaforementioned aspect; and an image sensor; wherein the image sensor ispositioned on or near an image surface of the imaging optical system.

According to still yet another aspect of the present disclosure, anelectronic device includes the image capturing device according to theaforementioned aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be more fully understood by reading the followingdetailed description of the embodiments, with reference made to theaccompanying drawings as follows:

FIG. 1A is a schematic view of an image capturing device according tothe 1st embodiment of the present disclosure;

FIG. 1B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 1stembodiment;

FIG. 2A is a schematic view of an image capturing device according tothe 2nd embodiment of the present disclosure;

FIG. 2B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 2ndembodiment;

FIG. 3A is a schematic view of an image capturing device according tothe 3rd embodiment of the present disclosure;

FIG. 3B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 3rdembodiment;

FIG. 4A is a schematic view of an image capturing device according tothe 4th embodiment of the present disclosure;

FIG. 4B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 4thembodiment;

FIG. 5A is a schematic view of an image capturing device according tothe 5th embodiment of the present disclosure;

FIG. 5B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 5thembodiment;

FIG. 6A is a schematic view of an image capturing device according tothe 6th embodiment of the present disclosure;

FIG. 6B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 6thembodiment;

FIG. 7A is a schematic view of an image capturing device according tothe 7th embodiment of the present disclosure;

FIG. 7B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 7thembodiment;

FIG. 8A is a schematic view of an image capturing device according tothe 8th embodiment of the present disclosure;

FIG. 8B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 8thembodiment;

FIG. 9A is a schematic view of an image capturing device according tothe 9th embodiment of the present disclosure;

FIG. 9B shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing device according to the 9thembodiment;

FIG. 10 shows Yc61 and Yc62 of the present disclosure.

FIG. 11A shows a smart phone with an image capturing device of thepresent disclosure installed therein;

FIG. 11B shows a tablet personal computer with an image capturing deviceof the present disclosure installed therein; and

FIG. 11C shows a wearable device with an image capturing device of thepresent disclosure installed therein.

DETAILED DESCRIPTION

An imaging optical system includes, in order from an object side to animage side, a first lens element, a second lens element, a third lenselement, a fourth lens element, a fifth lens element, and a sixth lenselement. The imaging optical system has a total of six lens elementswith refractive power.

In the aforesaid imaging optical system, every two lens elements of thefirst lens element, the second lens element, the third lens element, thefourth lens element, the fifth lens element, and the sixth lens elementhave at least one air gap in between. Each of the first through sixthlens elements is a single and non-cemented lens element. That is, anytwo lens elements adjacent to each other are not cemented, and there isa space between the two lens elements. Moreover, the manufacturingprocess of the cemented lenses is more complex than the non-cementedlenses. In particular, a second surface of one lens element and a firstsurface of the following lens element need to have accurate curvature toensure these two lens elements will be highly cemented. However, duringthe cementing process, those two lens elements might not be highlycemented due to displacement and it is thereby not favorable for theimage quality of the imaging optical system. Therefore, the imagingoptical system of the present disclosure provides six non-cemented lenselements for improving the problem generated by the cemented lenselements.

The first lens element has positive refractive power, so that itprovides the imaging optical system with the positive refractive poweras it needs to be so as to reduce the total track length of the imagingoptical system. The first lens element has an image-side surface beingconcave in a paraxial region thereof, so that it is favorable forcorrecting the astigmatism of the imaging optical system.

The second lens element can have negative refractive power, so that itis favorable for correcting the aberration created by the first lenselement. The second lens element may have an object-side surface beingconvex in a paraxial region thereof and an image-side surface beingconcave in a paraxial region thereof so that the astigmatism of thesystem can be effectively corrected and the image quality can beimproved.

The third lens element may have positive refractive power in a paraxialregion, which is favorable for distributing the refractive power of thefirst lens element and is favorable for reducing the sensitivity of thesystem. The third lens element may have an image-side surface beingconvex in a paraxial region, so that it is favorable for correcting theastigmatism and high order aberration as well as distributing therefractive power of the first lens element.

The fourth lens element may have negative refractive power in a paraxialregion thereof and an object-side surface being convex in a paraxialregion thereof, so that the curvature of the fourth lens element can beprevented from excessively strong and the spherical aberration can bereduced. At least one of the object-side and image-side surfaces of thefourth lens element has at least one inflection point, which isfavorable for correcting off-axis aberration.

The fifth lens element may have negative refractive power in a paraxialregion thereof, an object-side surface being concave in a paraxialregion thereof, and an image-side surface being convex in a paraxialregion thereof, which is favorable for correcting the aberration andchromatic aberration of the system.

The sixth lens element has positive refractive power in a paraxialregion thereof, which is effectively for the distribution of therefractive power of the system so that the sensitivity of the system canbe reduced and the manufacturing yield rate can be improved. The sixthlens element may have an object-side surface being convex in a paraxialregion thereof and an image-side surface being concave in a paraxialregion thereof so that the astigmatism can be favorably corrected. Theimage-side surface of the sixth lens element has at least one inflectionpoint, which is favorable for shortening the back focal length of thesystem to keep the imaging optical system compact.

In the aforesaid imaging optical system, among the object-side surfacesand the image-side surfaces of the first through the sixth lenselements, at least five surfaces has at least one inflection point oneach surface. Therefore, it is favorable for keeping the imaging opticalsystem compact and reducing the peripheral aberration so as to improvethe resolving power.

When a focal length of the imaging optical system is f, a curvatureradius of the image-side surface of the fourth lens element is R8, andthe following condition is satisfied: −0.50<f/R8, it is favorable formoderating the converging ability of the fourth lens element. Therefore,the curvature of the image-side surface of the fourth lens element canbe prevented from excessively strong and thereby the sphericalaberration can be reduced. It is thereby favorable for improving theresolving power of the imaging optical system. Preferably, the followingcondition is satisfied: −0.20<f/R8. More preferably, the followingcondition is satisfied: 0.0<f/R8.

When an axial distance between the fourth lens element and the fifthlens element is T45, a central thickness of the fifth lens element isCT5, and the following condition is satisfied: 0.30<T45/CT5. Thesensitivity of the imaging optical system is more suitable, which isfavorable for improving the manufacturing yield rate.

When a curvature radius of the object-side surface of the fifth lenselement is R9, a curvature radius of the image-side surface of the fifthlens element is R10, and the following condition is satisfied:(R9+R10)/(R9−R10)<2.0. Therefore, the shape of the fifth lens element isfavorable for correcting the astigmatism and aberration of imagingoptical the system. Preferable, the following condition is satisfied:(R9+R10)/(R9−R10)<−3.0.

When the imaging optical system further includes a stop, an axialdistance between the stop and the image-side surface of the sixth lenselement is SD, an axial distance between the object-side surface of thefirst lens element and the image-side surface of the sixth lens elementis TD, and the following condition is satisfied: 0.75<SD/TD<1.1.Therefore, it is favorable to obtain a balance between telecentricityand wide field of view.

When an f-number of the imaging optical system is Fno, and the followingcondition is satisfied: 1.50<Fno<2.50. Therefore, it is favorable forlarge aperture and improving the illumination in a peripheral region ofthe imaging optical system.

When a central thickness of the third lens element is CT3, a centralthickness of the second lens element is CT2, the following condition issatisfied: 1.40<CT3/CT2. Therefore, the thicknesses of the second lenselement and the third lens element will be favorable for avoiding thelens element from being deformed during manufacturing process so as toimprove the manufacturing yield rate.

When the focal length of the imaging optical system is f, a focal lengthof the third lens element is f3, a focal length of the fourth lenselement is f4, and the following condition is satisfied:0.1<(f/f3)+(f/f4). Therefore, the refractive power of the third lenselement and the fourth lens element is configured to favorably reducethe spherical aberration and the resolving power of the imaging opticalsystem is thereby improved.

When an axial distance between the object-side surface of the first lenselement and an image surface is TL, a maximal image height of theimaging optical system is ImgH, and the following condition issatisfied: TL/ImgH<1.80. Therefore, it is favorable for keeping thesystem compact to be applied to portable electronic devices.

When half of the maximal field of view of the imaging optical system isHFOV, and the following condition is satisfied: 38.0 degrees<HFOV.Therefore, it is favorable for the imaging optical system to obtain awide field of view.

When the focal length of the imaging optical system is f, a focal lengthof the third lens element is f3, a focal length of the fourth lenselement is f4, a focal length of the fifth lens element is f5, a focallength of the sixth lens element is f6, and the following condition issatisfied: 0.6<|f/f3|+|f/f4|+|f/f5|+|f/f6|<1.7. Therefore, theconfiguration of the refractive powers of the imaging optical system ismore balanced, so that the sensitivity of the system can thus befavorably reduced.

When a focal length of the imaging optical system is f, a curvatureradius of the image-side surface of the fifth lens element is R10, andthe following condition is satisfied: f/R10<−1.5. Therefore, it isfavorable for improving the resolving power of the imaging opticalsystem.

When a vertical distance between a non-axial critical point on theobject-side surface of the sixth lens element and an optical axis isYc61, a vertical distance between a non-axial critical point on theimage-side surface of the sixth lens element and an optical axis isYc62, and the following condition is satisfied: 0.2<Yc61/Yc62<0.9.Therefore, it is favorable for reducing the incident angle of the lightprojecting onto an image sensor so as to correct the aberration of theoff-axis.

According to the imaging optical system of the present disclosure, thelens elements thereof can be made of glass or plastic material. When thelens elements are made of glass material, the distribution of therefractive power of the imaging optical system may be more flexible todesign. When the lens elements are made of plastic material, themanufacturing cost can be effectively reduced. Furthermore, surfaces ofeach lens element can be arranged to be aspheric (ASP), since theaspheric surface of the lens element is easy to form a shape other thanspherical surfaces so as to have more controllable variables foreliminating the aberration thereof, and to further decrease the requirednumber of the lens elements. Therefore, the total track length of theimaging optical system can also be reduced.

According to the imaging optical system of the present disclosure, eachof an object-side surface and an image-side surface has a paraxialregion and an off-axis region. The paraxial region refers to the regionof the surface where light rays travel close to the optical axis, andthe off-axis region refers to the region of the surface away from theparaxial region. Particularly, when the lens element has a convexsurface, it indicates that the surface is convex in the paraxial regionthereof; when the lens element has a concave surface, it indicates thatthe surface is concave in the paraxial region thereof. Likewise, whenthe region of refractive power or focus of a lens element is notdefined, it indicates that the region of refractive power or focus ofthe lens element is in the paraxial region thereof.

According to the imaging optical system of the present disclosure, animage surface of the imaging optical system, based on the correspondingimage sensor, can be flat or curved, especially a curved surface beingconcave facing towards the object side of the optical imaging system.

According to the imaging optical system of the present disclosure, theimaging optical system can include at least one stop, such as anaperture stop, a glare stop or a field stop. Said glare stop or saidfield stop is for eliminating the stray light and thereby improving theimage resolution thereof.

According to the imaging optical system of the present disclosure, anaperture stop can be configured as a front stop or a middle stop. Afront stop disposed between an imaged object and the first lens elementcan provide a longer distance between an exit pupil of the imagingoptical system and the image surface and thereby improves theimage-sensing efficiency of an image sensor. A middle stop disposedbetween the first lens element and the image surface is favorable forenlarging the field of view of the imaging optical system and therebyprovides a wider field of view for the same.

Please refer to the FIG. 10 of the present disclosure, which shows thedistance defined as Yc61 and Yc62 of the present disclosure. As shown inthe embodiment of FIG. 10, when a vertical distance between a non-axialcritical point 1002 on the object-side surface 1061 of the sixth lenselement 1060 and an optical axis 1001 is Yc61; when a vertical distancebetween a non-axial critical point 1003 on the image-side surface 1062of the sixth lens element 1060 and an optical axis 1001 is Yc62. Saidcritical point is a non-axial point of the lens surface where itstangent is perpendicular to the optical axis.

The present imaging optical system can be optionally applied to movingfocus optical systems. According to the imaging optical system of thepresent disclosure, the imaging optical system is featured with goodcorrection ability and high image quality, and can be applied to 3D(three-dimensional) image capturing applications, in products such asdigital cameras, mobile devices, digital tablets, smart TV, wirelessmonitoring device, motion sensing input device, driving recordingsystem, rear view camera system, wearable devices and other electronicdevices.

According to the present disclosure, an image capturing device isprovided. The image capturing device includes the imaging optical systemaccording to the aforementioned imaging optical system of the presentdisclosure, and an image sensor, wherein the image sensor is disposed onor near an image surface of the aforementioned imaging optical system.As a result, it is favorable for improving the resolving power andillumination so as to achieve the best image quality. Preferably, theimage capturing device can further include a barrel member, a holdingmember or a combination thereof.

In FIG. 11A, FIG. 11B and FIG. 11C, an image capturing device 1101 maybe installed in but not limited to an electronic device, including asmart phone 1110, a tablet personal computer 1120 or a wearable device1130. The three exemplary figures of different kinds of electronicdevice are only exemplary for showing the image capturing device ofpresent disclosure installing in an electronic device and is not limitedthereto. Preferably, the electronic device can further include but notlimited to display, control unit, random access memory unit (RAM) a readonly memory unit (ROM) or a combination thereof.

According to the above description of the present disclosure, thefollowing 1st-9th specific embodiments are provided for furtherexplanation.

1st Embodiment

FIG. 1A is a schematic view of an image capturing device according tothe 1st embodiment of the present disclosure. FIG. 1B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the1st embodiment.

In FIG. 1A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 190. The imaging optical system includes, in order from anobject side to an image side, a first lens element 110, an aperture stop100, a second lens element 120, a third lens element 130, a fourth lenselement 140, a fifth lens element 150, a sixth lens element 160, anIR-cut filter 170 and an image surface 180, wherein the imaging opticalsystem has a total of six lens elements (110-160) with refractive power,which are non-cemented lens element.

The first lens element 110 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 111 in a paraxialregion thereof and an image-side surface being concave 112 in a paraxialregion thereof, which are both aspheric, the first lens element 110 ismade of plastic material, and both of the object-side surface 111 andthe image-side surface 112 of the first lens element 110 have at leastone inflection point.

The second lens element 120 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 121 in a paraxialregion thereof and an image-side surface being concave 122 in a paraxialregion thereof, which are both aspheric, and the second lens element 120is made of plastic material.

The third lens element 130 with positive refractive power in a paraxialregion thereof has an object-side surface being concave 131 in aparaxial region thereof and an image-side surface being convex 132 in aparaxial region thereof, which are both aspheric, the third lens element130 is made of plastic material, and both of the object-side surface 131and the image-side surface 132 of the third lens element 130 have atleast one inflection point.

The fourth lens element 140 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 141 in a paraxialregion thereof and an image-side surface being concave 142 in a paraxialregion thereof, which are both aspheric, the fourth lens element 140 ismade of plastic material, and both of the object-side surface 141 andthe image-side surface 142 of the fourth lens element 140 have at leastone inflection point.

The fifth lens element 150 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 151 in aparaxial region thereof and an image-side surface being convex 152 in aparaxial region thereof, which are both aspheric, the fifth lens element150 is made of plastic material, and both of the object-side surface 151and the image-side surface 152 of the fifth lens element 150 have atleast one inflection point.

The sixth lens element 160 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 161 in a paraxialregion thereof and an image-side surface being concave 162 in a paraxialregion thereof, which are both aspheric, the sixth lens element 160 ismade of plastic material, and both of the object-side surface 161 andthe image-side surface 162 of the sixth lens element 160 have at leastone inflection point.

The IR-cut filter 170 is made of glass and located between the sixthlens element 160 and the image surface 180, and will not affect thefocal length of the imaging optical system. The image sensor 190 isdisposed on or near the image surface 180 of the imaging optical system.

The equation of the aspheric surface profiles of the aforementioned lenselements of the 1st embodiment is expressed as follows:

${{X(Y)} = {{( {Y^{2}\text{/}R} )\text{/}( {1 + {{sqrt}( {1 - {( {1 + k} ) \times ( {Y\text{/}R} )^{2}}} )}} )} + {\sum\limits_{i}{({Ai}) \times ( Y^{i} )}}}},$

where,

X is the relative distance between a point on the aspheric surfacespaced at a distance Y from the optical axis and the tangential plane atthe aspheric surface vertex on the optical axis;

Y is the vertical distance from the point on the aspheric surface to theoptical axis;

R is the curvature radius;

k is the conic coefficient; and

Ai is the i-th aspheric coefficient.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when a focal length of the imaging optical system isf, an f-number of the imaging optical system is Fno, and half of amaximal field of view of the imaging optical system is HFOV, theseparameters have the following values: f=4.71 mm; Fno=2.25; and HFOV=37.0degrees.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when a central thickness of the third lens element130 is CT3, a central thickness of the second lens element 120 is CT2,the following condition is satisfied: CT3/CT2=1.73.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when an axial distance between the fourth lenselement 140 and the fifth lens element 150 is T45, a central thicknessof the fifth lens element 150 is CT5, the following condition issatisfied: T45/CT5=1.58.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when a focal length of the imaging optical system isf, a curvature radius of the image-side surface 142 of the fourth lenselement 140 is R8, the following condition is satisfied: f/R8=0.86.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when a focal length of the imaging optical system isf, a curvature radius of the image-side surface 152 of the fifth lenselement 150 is R10, the following condition is satisfied: f/R10=−3.15.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when a curvature radius of the object-side surface151 of the fifth lens element 150 is R9, a curvature radius of theimage-side surface 152 of the fifth lens element 150 is R10, thefollowing condition is satisfied: (R9+R10)/(R9−R10)=−7.14

In the imaging optical system of the image capturing device according tothe 1st embodiment, when the focal length of the imaging optical systemis f, a focal length of the third lens element 130 is f3, a focal lengthof the fourth lens element 140 is f4, the following condition issatisfied: (f/f3)+(f/f4)=0.55.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when the focal length of the imaging optical systemis f, the focal length of the third lens element 130 is f3, the focallength of the fourth lens element 140 is f4, a focal length of the fifthlens element 150 is f5, a focal length of the sixth lens element 160 isf6, the following condition is satisfied:|f/f3|+|f/f4|+|f/f5|+|f/f6|=1.29.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when a vertical distance between a non-axialcritical point on the object-side surface 161 of the sixth lens element160 and an optical axis is Yc61; when a vertical distance between anon-axial critical point on the image-side surface 162 of the sixth lenselement 160 and an optical axis is Yc62, the following condition issatisfied: Yc61/Yc62=0.59.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when an axial distance between the stop 100 and theimage-side surface 162 of the sixth lens element 160 is SD, an axialdistance between the object-side surface 111 of the first lens element110 and the image-side surface 162 of the sixth lens element 160 is TD,the following condition is satisfied: SD/TD=0.82.

In the imaging optical system of the image capturing device according tothe 1st embodiment, when an axial distance between the object-sidesurface 111 of the first lens element 110 and the image surface 180 isTL, a maximal image height of the imaging optical system is ImgH (i.e.half of a diagonal length of an effective photosensitive area of theimage sensor 190), the following condition is satisfied: TL/ImgH=1.65.

The detailed optical data of the 1st embodiment are shown in Table 1 andthe aspheric surface data are shown in Table 2 below.

TABLE 1 (Embodiment 1) f = 4.71 mm, Fno = 2.25, HFOV = 37.0 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 1.946 ASP 0.716 Plastic 1.544 55.9 4.242 10.787 ASP 0.115 3 Ape. Stop Plano 0.038 4 Lens 2 4.028 ASP 0.277Plastic 1.640 23.3 −7.57 5 2.139 ASP 0.380 6 Lens 3 −33.050 ASP 0.480Plastic 1.544 55.9 7.94 7 −3.842 ASP 0.045 8 Lens 4 6.135 ASP 0.261Plastic 1.544 55.9 −112.29 9 5.492 ASP 0.523 10 Lens 5 −1.129 ASP 0.330Plastic 1.640 23.3 −11.06 11 −1.497 ASP 0.050 12 Lens 6 2.352 ASP 1.431Plastic 1.535 55.7 20.90 13 2.346 ASP 0.600 14 IR-cut filter Plano 0.200Glass 1.517 64.2 — 15 Plano 0.504 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 2 Aspheric Coefficients Surface # 1 2 4 5 6 7 k = −1.2376E−01−2.9648E+01 −3.0000E+01 −8.7875E+00  −1.5749E+01  1.9052E+00 A4 =−4.8953E−04 −5.5703E−02 −8.8932E−02 5.6313E−03 −1.9923E−02 −2.6020E−02A6 =  3.6053E−03  5.3408E−02  8.8695E−02 2.7231E−02 −3.5590E−02−2.4936E−02 A8 = −4.9337E−03 −3.1040E−02 −1.7762E−02 2.0834E−02 2.5682E−02 −3.9548E−03 A10 = −1.3998E−03  5.0203E−03 −2.4531E−02−2.9247E−02  −4.9219E−02  9.1131E−05 A12 =  3.5748E−03  5.8242E−04 1.9311E−02 1.5494E−02  3.5770E−02  7.1888E−03 A14 = −1.8484E−03−3.9251E−04 −4.5225E−03 −8.9284E−04  Surface # 8 9 10 11 12 13 k = 2.1589E+00 −1.0000E+00 −5.2029E+00 −8.8850E−01  −2.3222E+01 −7.2949E+00A4 = −6.9536E−02 −4.1072E−02 −3.1473E−02 5.2415E−02 −6.3026E−02−2.9256E−02 A6 = −1.8000E−02 −1.1740E−02  2.1140E−03 −1.4562E−02  2.6051E−02  8.4586E−03 A8 =  2.9052E−03  4.8075E−03  1.5473E−026.3355E−03 −1.1264E−02 −2.3987E−03 A10 =  2.2083E−03  1.9469E−03−4.4506E−03 1.1385E−03  3.7636E−03  4.4706E−04 A12 =  1.8215E−03−8.3419E−04  4.7068E−05 −2.7117E−04  −7.0301E−04 −5.1986E−05 A14 = 1.3757E−03 −9.5945E−05  1.0676E−04 −1.3595E−04   6.6366E−05  3.4192E−06A16 = −1.3361E−03 −1.2244E−05 2.4027E−05 −2.5020E−06 −9.4722E−08

In Table 1, the curvature radius, the thickness and the focal length areshown in millimeters (mm). Surface numbers 0-16 represent the surfacessequentially arranged from the object-side to the image-side along theoptical axis. In Table 2, k represents the conic coefficient of theequation of the aspheric surface profiles. A4-A16 represent the asphericcoefficients ranging from the 4th order to the 16th order. The tablespresented below for each embodiment are the corresponding schematicparameter and aberration curves, and the definitions of the tables arethe same as Table 1 and Table 2 of the 1st embodiment. Therefore, anexplanation in this regard will not be provided again.

2nd Embodiment

FIG. 2A is a schematic view of an image capturing device according tothe 2nd embodiment of the present disclosure. FIG. 2B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the2nd embodiment.

In FIG. 2A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 290. The imaging optical system includes, in order from anobject side to an image side, an aperture stop 200, a first lens element210, a second lens element 220, a third lens element 230, a fourth lenselement 240, a fifth lens element 250, a sixth lens element 260, anIR-cut filter 270 and an image surface 280, wherein the imaging opticalsystem has a total of six lens elements (210-260) with refractive power,which are non-cemented lens element.

The first lens element 210 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 211 in a paraxialregion thereof and an image-side surface being concave 212 in a paraxialregion thereof, which are both aspheric, the first lens element 210 ismade of plastic material, and the image-side surface 212 of the secondlens element 210 has at least one inflection point.

The second lens element 220 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 221 in a paraxialregion thereof and an image-side surface being concave 222 in a paraxialregion thereof, which are both aspheric, and the second lens element 220is made of plastic material.

The third lens element 230 with positive refractive power in a paraxialregion thereof has an object-side surface being concave 231 in aparaxial region thereof and an image-side surface being convex 232 in aparaxial region thereof, which are both aspheric, the third lens element230 is made of plastic material, and both of the object-side surface 231and the image-side surface 232 of the third lens element 230 have atleast one inflection point.

The fourth lens element 240 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 241 in a paraxialregion thereof and an image-side surface being concave 242 in a paraxialregion thereof, which are both aspheric, the fourth lens element 240 ismade of plastic material, and both of the object-side surface 241 andthe image-side surface 242 of the fourth lens element 240 have at leastone inflection point.

The fifth lens element 250 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 251 in aparaxial region thereof and an image-side surface being convex 252 in aparaxial region thereof, which are both aspheric, the fifth lens element250 is made of plastic material, and both of the object-side surface 251and the image-side surface 252 of the fifth lens element 250 have atleast one inflection point.

The sixth lens element 260 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 261 in a paraxialregion thereof and an image-side surface being concave 262 in a paraxialregion thereof, which are both aspheric, the sixth lens element 260 ismade of plastic material, and both of the object-side surface 261 andthe image-side surface 262 of the sixth lens element 260 have at leastone inflection point.

The IR-cut filter 270 is made of glass and located between the sixthlens element 260 and the image surface 280, and will not affect thefocal length of the imaging optical system. The image sensor 290 isdisposed on or near the image surface 280 of the imaging optical system.

The detailed optical data of the 2nd embodiment are shown in Table 3 andthe aspheric surface data are shown in Table 4 below.

TABLE 3 (Embodiment 2) f = 4.10 mm, Fno = 2.28, HFOV = 38.3 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Ape. Stop Plano −0.273 2 Lens 1 1.588 ASP0.526 Plastic 1.544 55.9 3.49 3 8.559 ASP 0.087 4 Lens 2 3.579 ASP 0.260Plastic 1.650 21.4 −7.94 5 2.053 ASP 0.417 6 Lens 3 −7.649 ASP 0.422Plastic 1.544 55.9 8.04 7 −2.836 ASP 0.040 8 Lens 4 100.000 ASP 0.280Plastic 1.544 55.9 −32.88 9 15.161 ASP 0.339 10 Lens 5 −1.022 ASP 0.280Plastic 1.650 21.4 −9.68 11 −1.353 ASP 0.140 12 Lens 6 1.639 ASP 0.982Plastic 1.535 55.7 19.39 13 1.540 ASP 0.550 14 IR-cut filter Plano 0.183Glass 1.517 64.2 — 15 Plano 0.526 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 4 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = −1.6796E−02 −3.0000E+01 −8.8579E+00 −5.1744E+00  −2.3561E+01 −1.2975E+00 A4 =5.2509E−03 −6.0541E−02 −1.0272E−01 2.3206E−02 −2.3496E−02 −2.4413E−02 A6= 3.7251E−03  8.0994E−02  1.1809E−01 4.1835E−02 −5.2821E−02 −4.3946E−02A8 = −3.0059E−03  −6.4321E−02 −4.9414E−02 3.7705E−02  7.9653E−02 1.5648E−02 A10 = 1.2920E−03  1.7660E−02 −3.6747E−02 −7.0872E−02 −9.3420E−02  4.4518E−03 A12 = 3.3335E−03  1.5172E−02  6.4754E−026.0922E−02  6.9484E−02  1.3371E−02 A14 = −5.64383E−03  −1.58654E−02 −2.52473E−02  3.34424E−03  Surface # 8 9 10 11 12 13 k = −3.0000E+01 −1.0000E+00 −5.3021E+00 −1.0882E+00  −1.2884E+01 −6.9522E+00 A4 =−9.9209E−02  −7.6957E−02 −3.1285E−02 8.0519E−02 −9.4714E−02 −4.4798E−02A6 = −1.2426E−02  −9.3300E−04  1.2759E−03 −2.5065E−02   4.0530E−02 1.3103E−02 A8 = 1.0115E−04  8.3727E−03  2.7806E−02 1.0912E−02−2.0735E−02 −4.4092E−03 A10 = 4.9664E−03  1.8768E−03 −9.5256E−032.2738E−03  8.2539E−03  9.7971E−04 A12 = 4.9529E−03 −2.8641E−03 2.2363E−04 −7.3463E−04  −1.8288E−03 −1.3552E−04 A14 = 3.1699E−03 8.5286E−05  3.2621E−04 −4.1517E−04   2.0551E−04  1.0562E−05 A16 =−7.0718E−03  −7.2793E−05 9.2219E−05 −9.2819E−06 −3.5436E−07

In the 2nd embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 2nd embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 3 and Table 4 asthe following values and satisfy the following conditions:

2nd Embodiment f [mm] 4.10 (R9 + R10)/(R9 − R10) −7.20 Fno 2.28 (f/f3) +(f/f4) 0.39 HFOV [deg.] 38.3 |f/f3| + |f/f4| + |f/f5| + |f/f6| 1.27CT3/CT2 1.62 Yc61/Yc62 0.67 T45/CT5 1.21 SD/TD 0.93 f/R8 0.27 TL/ImgH1.52 f/R10 −3.03

3rd Embodiment

FIG. 3A is a schematic view of an image capturing device according tothe 3rd embodiment of the present disclosure. FIG. 3B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the3rd embodiment.

In FIG. 3A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 390. The imaging optical system includes, in order from anobject side to an image side, a first lens element 310, an aperture stop300, a second lens element 320, a third lens element 330, a fourth lenselement 340, a fifth lens element 350, a sixth lens element 360, anIR-cut filter 370 and an image surface 380, wherein the imaging opticalsystem has a total of six lens elements (310-360) with refractive power,which are non-cemented lens element.

The first lens element 310 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 311 in a paraxialregion thereof and an image-side surface being concave 312 in a paraxialregion thereof, which are both aspheric, the first lens element 310 ismade of plastic material, and both of the object-side surface 311 andthe image-side surface 312 of the first lens element 310 have at leastone inflection point.

The second lens element 320 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 321 in a paraxialregion thereof and an image-side surface being concave 322 in a paraxialregion thereof, which are both aspheric, the second lens element 320 ismade of plastic material, and the object-side surface 321 of the secondlens element 320 has at least one inflection point.

The third lens element 330 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 331 in a paraxialregion thereof and an image-side surface being concave 332 in a paraxialregion thereof, which are both aspheric, the third lens element 330 ismade of plastic material, and both of the object-side surface 331 andthe image-side surface 332 of the third lens element 330 have at leastone inflection point.

The fourth lens element 340 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 341 in a paraxialregion thereof and an image-side surface being concave 342 in a paraxialregion thereof, which are both aspheric, the fourth lens element 340 ismade of plastic material, and both of the object-side surface 341 andthe image-side surface 342 of the fourth lens element 340 have at leastone inflection point.

The fifth lens element 350 with positive refractive power in a paraxialregion thereof has an object-side surface being concave 351 in aparaxial region thereof and an image-side surface being convex 352 in aparaxial region thereof, which are both aspheric, the fifth lens element350 is made of plastic material, and both of the object-side surface 351and the image-side surface 352 of the fifth lens element 350 have atleast one inflection point.

The sixth lens element 360 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 361 in a paraxialregion thereof and an image-side surface being concave 362 in a paraxialregion thereof, which are both aspheric, the sixth lens element 360 ismade of plastic material, and both of the object-side surface 361 andthe image-side surface 362 of the sixth lens element 360 have at leastone inflection point.

The IR-cut filter 370 is made of glass and located between the sixthlens element 360 and the image surface 380, and will not affect thefocal length of the imaging optical system. The image sensor 390 isdisposed on or near the image surface 380 of the imaging optical system.

The detailed optical data of the 3rd embodiment are shown in Table 5 andthe aspheric surface data are shown in Table 6 below.

TABLE 5 (Embodiment 3) f = 4.74 mm, Fno = 2.20, HFOV = 36.4 degCurvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 1.956 ASP 0.701 Plastic 1.544 55.9 3.942 19.528 ASP 0.045 3 Ape. Stop Plano 0.032 4 Lens 2 5.172 ASP 0.240Plastic 1.640 23.3 −7.23 5 2.397 ASP 0.398 6 Lens 3 30.670 ASP 0.365Plastic 1.544 55.9 210.27 7 41.726 ASP 0.235 8 Lens 4 3.016 ASP 0.315Plastic 1.544 55.9 21.90 9 3.889 ASP 0.555 10 Lens 5 −1.411 ASP 0.393Plastic 1.544 55.9 150.22 11 −1.523 ASP 0.050 12 Lens 6 2.188 ASP 1.142Plastic 1.535 55.7 172.78 13 1.834 ASP 0.600 14 IR-cut filter Plano0.200 Glass 1.517 64.2 — 15 Plano 0.625 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 6 Aspheric Coefficients Surface # 1 2 4 5 6 7 k = −8.6729E−023.0000E+00 −1.5490E+01 −6.3207E+00 3.0000E+00 3.0000E+00 A4 = 1.6725E−03−5.6043E−02 −1.0190E−01 −7.3839E−03 −7.8835E−03 −5.0116E−02 A6 =2.1900E−03 5.3370E−02 8.6736E−02 1.4285E−02 −4.3196E−02 4.3814E−04 A8 =−3.2743E−03 −3.1864E−02 −2.0543E−02 2.0993E−02 3.2410E−02 −9.6348E−03A10 = −1.5989E−03 6.1535E−03 −1.9651E−02 −2.5055E−02 −5.2262E−02−4.5452E−03 A12 = 2.8519E−03 2.5376E−04 2.3820E−02 1.4700E−02 2.9588E−026.9418E−03 A14 = −1.7944E−03 −3.5538E−04 −7.2111E−03 −2.7394E−04 Surface# 8 9 10 11 12 13 k = −3.6054E+00 −1.0000E+00 −8.2723E+00 −7.3546E−01−1.4063E+01 −5.4606E+00 A4 = −7.1792E−02 −2.1818E−02 −1.9900E−023.6913E−02 −7.0662E−02 −3.5878E−02 A6 = −9.5484E−03 −2.3499E−02−3.6439E−04 −1.6036E−02 2.6141E−02 9.8724E−03 A8 = −2.9556E−035.2323E−03 1.3355E−02 6.7622E−03 −1.1210E−02 −2.5913E−03 A10 =−1.8234E−03 2.8101E−03 −4.7593E−03 1.2158E−03 3.7714E−03 4.5718E−04 A12= 2.0584E−03 −8.3953E−04 3.5695E−05 −2.6598E−04 −7.0303E−04 −5.1376E−05A14 = 2.1996E−03 −5.5393E−05 1.1733E−04 −1.3702E−04 6.6227E−053.3528E−06 A16 = −1.0954E−03 −6.4194E−06 2.4006E−05 −2.5166E−06−9.5884E−08

In the 3rd embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 3rd embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 5 and Table 6 asthe following values and satisfy the following conditions:

3rd Embodiment f [mm] 4.74 (R9 + R10)/(R9 − R10) −26.15 Fno 2.20(f/f3) + (f/f4) 0.24 HFOV [deg.] 36.4 |f/f3| + |f/f4| + |f/f5| + |f/f6|0.30 CT3/CT2 1.52 Yc61/Yc62 0.60 T45/CT5 1.41 SD/TD 0.83 f/R8 1.22TL/ImgH 1.64 f/R10 −3.11

4th Embodiment

FIG. 4A is a schematic view of an image capturing device according tothe 4th embodiment of the present disclosure. FIG. 4B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the4th embodiment.

In FIG. 4A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 490. The imaging optical system includes, in order from anobject side to an image side, a first lens element 410, an aperture stop400, a second lens element 420, a third lens element 430, a fourth lenselement 440, a fifth lens element 450, a sixth lens element 460, anIR-cut filter 470 and an image surface 480, wherein the imaging opticalsystem has a total of six lens elements (410-460) with refractive power,which are non-cemented lens element.

The first lens element 410 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 411 in a paraxialregion thereof and an image-side surface being concave 412 in a paraxialregion thereof, which are both aspheric, the first lens element 410 ismade of plastic material, and both of the object-side surface 411 andthe image-side surface 412 of the first lens element 410 have at leastone inflection point.

The second lens element 420 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 421 in a paraxialregion thereof and an image-side surface being concave 422 in a paraxialregion thereof, which are both aspheric, the second lens element 420 ismade of plastic material, and the object-side surface 421 of the secondlens element 420 has at least one inflection point.

The third lens element 430 with positive refractive power in a paraxialregion thereof has an object-side surface being concave 431 in aparaxial region thereof and an image-side surface being convex 432 in aparaxial region thereof, which are both aspheric, the third lens element430 is made of plastic material, and both of the object-side surface 431and the image-side surface 432 of the third lens element 430 have atleast one inflection point.

The fourth lens element 440 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 441 in a paraxialregion thereof and an image-side surface being concave 442 in a paraxialregion thereof, which are both aspheric, the fourth lens element 440 ismade of plastic material, and both of the object-side surface 441 andthe image-side surface 442 of the fourth lens element 440 have at leastone inflection point.

The fifth lens element 450 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 451 in aparaxial region thereof and an image-side surface being convex 452 in aparaxial region thereof, which are both aspheric, the fifth lens element450 is made of plastic material, and both of the object-side surface 451and the image-side surface 452 of the fifth lens element 450 have atleast one inflection point.

The sixth lens element 460 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 461 in a paraxialregion thereof and an image-side surface being concave 462 in a paraxialregion thereof, which are both aspheric, the sixth lens element 460 ismade of plastic material, and both of the object-side surface 461 andthe image-side surface 462 of the sixth lens element 460 have at leastone inflection point.

The IR-cut filter 470 is made of glass and located between the sixthlens element 460 and the image surface 480, and will not affect thefocal length of the imaging optical system. The image sensor 490 isdisposed on or near the image surface 480 of the imaging optical system.

The detailed optical data of the 4th embodiment are shown in Table 7 andthe aspheric surface data are shown in Table 8 below.

TABLE 7 (Embodiment 4) f = 5.01 mm, Fno = 2.00, HFOV = 35.0 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.135 ASP 0.867 Plastic 1.544 55.9 4.192 28.413 ASP 0.076 3 Ape. Stop Plano −0.026 4 Lens 2 4.107 ASP 0.240Plastic 1.640 23.3 −7.16 5 2.116 ASP 0.412 6 Lens 3 −27.946 ASP 0.535Plastic 1.544 55.9 464.42 7 −25.333 ASP 0.201 8 Lens 4 3.599 ASP 0.497Plastic 1.544 55.9 10.20 9 9.735 ASP 0.765 10 Lens 5 −1.224 ASP 0.369Plastic 1.544 55.9 −14.77 11 −1.597 ASP 0.050 12 Lens 6 1.794 ASP 1.000Plastic 1.535 55.7 33.62 13 1.605 ASP 0.600 14 IR-cut filter Plano 0.200Glass 1.517 64.2 — 15 Plano 0.505 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 8 Aspheric Coefficients Surface # 1 2 4 5 6 7 k = −2.2785E−02−3.0000E+01 −1.5383E+00 −4.4543E+00 −3.0000E+01  3.0000E+00 A4 = 3.6870E−03 −3.1482E−02 −1.0065E−01 −1.4482E−02 −6.3867E−03 −7.8856E−02A6 = −1.4207E−03  4.6828E−02  6.1147E−02 −1.0406E−03 −3.8791E−02 6.4645E−03 A8 =  2.7996E−03 −3.4597E−02 −1.6412E−02  2.1903E−02 4.6639E−02 −5.5884E−03 A10 = −9.1188E−04  1.2151E−02 −1.7312E−02−2.1535E−02 −5.3344E−02  5.2117E−04 A12 = −1.0287E−04 −2.4616E−04 2.0285E−02  8.0771E−03  2.3590E−02  2.3063E−03 A14 =  1.2364E−04−5.8028E−04 −6.0231E−03  9.0011E−04 Surface # 8 9 10 11 12 13 k =−6.0829E−01 −1.0000E+00 −7.6111E+00 −5.6575E−01 −1.3040E+01 −5.4087E+00A4 = −6.8743E−02  7.6515E−03 −4.1197E−02  3.8342E−02 −7.8870E−02−3.6041E−02 A6 = −1.0825E−02 −2.5087E−02 −7.3067E−03 −1.9952E−02 2.7434E−02  1.0290E−02 A8 = −2.6535E−03  1.7813E−03  1.6033E−02 6.1135E−03 −1.1677E−02 −2.7380E−03 A10 = −1.6006E−03  1.9891E−03−4.5683E−03  1.3683E−03  3.7974E−03  4.7626E−04 A12 =  1.0115E−03−8.3235E−04 −1.2575E−04 −2.0682E−04 −6.9518E−04 −5.1947E−05 A14 = 1.7511E−03  9.0906E−05  8.2435E−05 −1.2981E−04  6.6459E−05  3.2537E−06A16 = −6.9981E−04  8.4330E−06  2.0785E−05 −2.6706E−06 −8.8821E−08

In the 4th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 4th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 7 and Table 8 asthe following values and satisfy the following conditions:

4th Embodiment f [mm] 5.01 (R9 + R10)/(R9 − R10) −7.56 Fno 2.00 (f/f3) +(f/f4) 0.50 HFOV [deg.] 35.0 |f/f3| + |f/f4| + |f/f5| + |f/f6| 0.99CT3/CT2 2.23 Yc61/Yc62 0.57 T45/CT5 2.07 SD/TD 0.81 f/R8 0.51 TL/ImgH1.75 f/R10 −3.14

5th Embodiment

FIG. 5A is a schematic view of an image capturing device according tothe 5th embodiment of the present disclosure. FIG. 5B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the5th embodiment.

In FIG. 5A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 590. The imaging optical system includes, in order from anobject side to an image side, a first lens element 510, an aperture stop500, a second lens element 520, a third lens element 530, a fourth lenselement 540, a fifth lens element 550, a sixth lens element 560, anIR-cut filter 570 and an image surface 580, wherein the imaging opticalsystem has a total of six lens elements (510-560) with refractive power,which are non-cemented lens element.

The first lens element 510 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 511 in a paraxialregion thereof and an image-side surface being convex 512 in a paraxialregion thereof, which are both aspheric, the first lens element 510 ismade of plastic material, and the object-side surface 511 of the firstlens element 510 has at least one inflection point.

The second lens element 520 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 521 in a paraxialregion thereof and an image-side surface being concave 522 in a paraxialregion thereof, which are both aspheric, and the second lens element 520is made of plastic material.

The third lens element 530 with positive refractive power in a paraxialregion thereof has an object-side surface being concave 531 in aparaxial region thereof and an image-side surface being convex 532 in aparaxial region thereof, which are both aspheric, the third lens element530 is made of plastic material, and both of the object-side surface 531and the image-side surface 532 of the third lens element 530 have atleast one inflection point.

The fourth lens element 540 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 541 in a paraxialregion thereof and an image-side surface being concave 542 in a paraxialregion thereof, which are both aspheric, the fourth lens element 540 ismade of plastic material, and both of the object-side surface 541 andthe image-side surface 542 of the fourth lens element 540 have at leastone inflection point.

The fifth lens element 550 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 551 in aparaxial region thereof and an image-side surface being convex 552 in aparaxial region thereof, which are both aspheric, the fifth lens element550 is made of plastic material, and the image-side surface 552 of thefifth lens element 550 has at least one inflection point.

The sixth lens element 560 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 561 in a paraxialregion thereof and an image-side surface being concave 562 in a paraxialregion thereof, which are both aspheric, the sixth lens element 560 ismade of plastic material, and both of the object-side surface 561 andthe image-side surface 562 of the sixth lens element 560 have at leastone inflection point.

The IR-cut filter 570 is made of glass and located between the sixthlens element 560 and the image surface 580, and will not affect thefocal length of the imaging optical system. The image sensor 590 isdisposed on or near the image surface 580 of the imaging optical system.

The detailed optical data of the 5th embodiment are shown in Table 9 andthe aspheric surface data are shown in Table 10 below.

TABLE 9 (Embodiment 5) f = 4.97 mm, Fno = 2.20, HFOV = 35.0 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.226 ASP 0.742 Plastic 1.544 55.9 3.932 −47.506 ASP 0.045 3 Ape. Stop Plano 0.005 4 Lens 2 4.060 ASP 0.240Plastic 1.640 23.3 −6.66 5 2.030 ASP 0.431 6 Lens 3 −13.781 ASP 0.578Plastic 1.544 55.9 773.50 7 −13.542 ASP 0.207 8 Lens 4 3.286 ASP 0.566Plastic 1.544 55.9 11.85 9 6.296 ASP 0.780 10 Lens 5 −1.178 ASP 0.343Plastic 1.544 55.9 −16.47 11 −1.495 ASP 0.050 12 Lens 6 1.771 ASP 1.000Plastic 1.535 55.7 33.41 13 1.579 ASP 0.600 14 IR-cut filter Plano 0.200Glass 1.517 64.2 — 15 Plano 0.503 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 10 Aspheric Coefficients Surface # 1 2 4 5 6 7 k = −1.6402E−01−3.0000E+01  1.5488E+00 −4.2139E+00 −7.1170E−01 −2.7178E+01 A4 = 9.5428E−04 −2.2801E−02 −9.2921E−02 −1.4123E−02 −5.7866E−03 −8.0415E−02A6 = −1.0219E−03  2.9509E−02  4.8227E−02  4.4715E−04 −3.7558E−02 9.2025E−03 A8 = −1.3766E−03 −2.9179E−02 −6.8103E−03  2.1494E−02 3.9278E−02 −4.7580E−03 A10 = −1.8517E−04  1.5792E−02 −1.4091E−02−1.9900E−02 −4.8715E−02 −4.0579E−04 A12 = −7.7639E−05 −4.7484E−03 1.7909E−02  1.0996E−02  2.5683E−02  2.5045E−03 A14 = −1.4092E−04 4.8414E−04 −6.2772E−03 −4.5826E−04 Surface # 8 9 10 11 12 13 k =−9.1389E−01 −1.0000E+00 −6.4643E+00 −5.3265E−01 −1.1635E+01 −5.2026E+00A4 = −7.1200E−02  5.0665E−03 −3.0145E−02  5.6319E−02 −7.4130E−02−3.6333E−02 A6 = −4.8038E−03 −2.2094E−02 −1.2112E−02 −1.8302E−02 3.1626E−02  1.1204E−02 A8 = −2.0006E−03  2.9198E−03  1.7350E−02 5.6458E−03 −1.3034E−02 −2.9103E−03 A10 = −2.0600E−04  1.7775E−03−4.2115E−03  1.3468E−03  3.7959E−03  4.9163E−04 A12 =  2.5870E−05−8.8184E−04 −1.1857E−04 −2.0054E−04 −6.7686E−04 −5.2524E−05 A14 = 1.1870E−03  9.2243E−05  6.8234E−05 −1.2703E−04  6.7579E−05  3.1855E−06A16 = −4.3122E−04  2.5848E−06  2.1612E−05 −2.9429E−06 −8.3228E−08

In the 5th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 5th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 9 and Table 10as the following values and satisfy the following conditions:

5th Embodiment f [mm] 4.97 (R9 + R10)/(R9 − R10) −8.42 Fno 2.20 (f/f3) +(f/f4) 0.43 HFOV [deg.] 35.0 |f/f3| + |f/f4| + |f/f5| + |f/f6| 0.88CT3/CT2 2.41 Yc61/Yc62 0.60 T45/CT5 2.27 SD/TD 0.84 f/R8 0.79 TL/ImgH1.75 f/R10 −3.33

6th Embodiment

FIG. 6A is a schematic view of an image capturing device according tothe 6th embodiment of the present disclosure. FIG. 6B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the6th embodiment.

In FIG. 6A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 690. The imaging optical system includes, in order from anobject side to an image side, a first lens element 610, an aperture stop600, a second lens element 620, a third lens element 630, a fourth lenselement 640, a fifth lens element 650, a sixth lens element 660, anIR-cut filter 670 and an image surface 680, wherein the imaging opticalsystem has a total of six lens elements (610-660) with refractive power,which are non-cemented lens element.

The first lens element 610 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 611 in a paraxialregion thereof and an image-side surface being concave 612 in a paraxialregion thereof, which are both aspheric, the first lens element 610 ismade of plastic material, and both of the object-side surface 611 andthe image-side surface 612 of the first lens element 610 have at leastone inflection point.

The second lens element 620 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 621 in a paraxialregion thereof and an image-side surface being concave 622 in a paraxialregion thereof, which are both aspheric, and the second lens element 620is made of plastic material.

The third lens element 630 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 631 in a paraxialregion thereof and an image-side surface being concave 632 in a paraxialregion thereof, which are both aspheric, the third lens element 630 ismade of plastic material, and both of the object-side surface 631 andthe image-side surface 632 of the third lens element 630 have at leastone inflection point.

The fourth lens element 640 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 641 in a paraxialregion thereof and an image-side surface being convex 642 in a paraxialregion thereof, which are both aspheric, the fourth lens element 640 ismade of plastic material, and the object-side surface 641 of the fourthlens element 640 has at least one inflection point.

The fifth lens element 650 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 651 in aparaxial region thereof and an image-side surface being convex 652 in aparaxial region thereof, which are both aspheric, the fifth lens element650 is made of plastic material, and both of the object-side surface 651and the image-side surface 652 of the fifth lens element 650 have atleast one inflection point.

The sixth lens element 660 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 661 in a paraxialregion thereof and an image-side surface being concave 662 in a paraxialregion thereof, which are both aspheric, the sixth lens element 660 ismade of plastic material, and both of the object-side surface 661 andthe image-side surface 662 of the sixth lens element 660 have at leastone inflection point.

The IR-cut filter 670 is made of glass and located between the sixthlens element 660 and the image surface 680, and will not affect thefocal length of the imaging optical system. The image sensor 690 isdisposed on or near the image surface 680 of the imaging optical system.

The detailed optical data of the 6th embodiment are shown in Table 11and the aspheric surface data are shown in Table 12 below.

TABLE 11 (Embodiment 6) f = 4.96 mm, Fno = 2.25, HFOV = 35.1 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 1.977 ASP 0.798 Plastic 1.544 55.9 3.662 210.602 ASP 0.103 3 Ape. Stop Plano −0.053 4 Lens 2 3.521 ASP 0.240Plastic 1.650 21.4 −6.22 5 1.831 ASP 0.368 6 Lens 3 76.853 ASP 0.354Plastic 1.639 23.5 −57.26 7 24.745 ASP 0.335 8 Lens 4 5.468 ASP 0.602Plastic 1.544 55.9 10.01 9 −1331.867 ASP 0.500 10 Lens 5 −1.216 ASP0.349 Plastic 1.544 55.9 −12.24 11 −1.638 ASP 0.133 12 Lens 6 1.457 ASP0.750 Plastic 1.535 55.7 19.85 13 1.386 ASP 0.600 14 IR-cut filter Plano0.200 Glass 1.517 64.2 — 15 Plano 0.707 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 12 Aspheric Coefficients Surface # 1 2 4 5 6 7 k = −1.3178E−01−3.0000E+01  2.7885E+00 −4.2812E+00  −3.0000E+01  3.0000E+00 A4 = 1.9976E−03 −3.9903E−03 −7.8085E−02 1.3621E−02 −3.6605E−02 −6.5302E−02A6 =  1.1970E−03  1.1594E−02  4.5122E−02 8.7693E−03 −9.1585E−03 1.3803E−02 A8 = −2.3814E−03 −1.8666E−02 −1.9062E−02 1.3198E−02 3.4910E−02 −2.0024E−03 A10 =  4.5295E−04  1.7439E−02 −4.8633E−03−1.9415E−02  −4.2167E−02  6.8109E−04 A12 =  3.7042E−04 −9.1321E−03 1.6287E−02 1.5726E−02  2.5755E−02  4.5403E−03 A14 = −2.8191E−04 1.8818E−03 −7.5118E−03 −2.0368E−03  Surface # 8 9 10 11 12 13 k = 3.0000E+00 −1.0000E+00 −7.0246E+00 −4.5586E−01  −7.0986E+00 −4.8321E+00A4 = −5.1424E−02  1.0582E−03 −3.1688E−02 4.9501E−02 −9.0946E−02−4.8811E−02 A6 = −7.7752E−03 −1.8216E−02 −1.5626E−02 −1.8563E−02  3.5626E−02  1.3595E−02 A8 = −1.0724E−03  8.6852E−04  1.6227E−025.7093E−03 −1.3815E−02 −3.3652E−03 A10 = −3.7094E−04  1.5993E−03−3.8885E−03 1.3704E−03  3.7490E−03  5.1738E−04 A12 = −1.9258E−04−7.6727E−04  3.2471E−05 −1.9421E−04  −6.5823E−04 −5.1433E−05 A14 = 1.2504E−03  1.0091E−04  9.0588E−05 −1.2685E−04   7.0080E−05  3.0162E−06A16 = −4.1406E−04 −6.2844E−06 2.0624E−05 −3.3853E−06 −7.6161E−08

In the 6th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 6th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 11 and Table 12as the following values and satisfy the following conditions:

6th Embodiment f [mm] 4.96 (R9 + R10)/(R9 − R10) −6.76 Fno 2.25 (f/f3) +(f/f4) 0.41 HFOV [deg.] 35.1 |f/f3| + |f/f4| + |f/f5| + |f/f6| 1.24CT3/CT2 1.48 Yc61/Yc62 0.72 T45/CT5 1.43 SD/TD 0.80 f/R8 −0.004 TL/ImgH1.66 f/R10 −3.03

7th Embodiment

FIG. 7A is a schematic view of an image capturing device according tothe 7th embodiment of the present disclosure. FIG. 7B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the7th embodiment.

In FIG. 7A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 790. The imaging optical system includes, in order from anobject side to an image side, an aperture stop 700, a first lens element710, a second lens element 720, a third lens element 730, a fourth lenselement 740, a fifth lens element 750, a sixth lens element 760, anIR-cut filter 770 and an image surface 780, wherein the imaging opticalsystem has a total of six lens elements (710-760) with refractive power,which are non-cemented lens element.

The first lens element 710 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 711 in a paraxialregion thereof and an image-side surface being concave 712 in a paraxialregion thereof, which are both aspheric, the first lens element 710 ismade of plastic material, and both of the object-side surface 711 andthe image-side surface 712 of the first lens element 710 have at leastone inflection point.

The second lens element 720 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 721 in aparaxial region thereof and an image-side surface being concave 722 in aparaxial region thereof, which are both aspheric, the second lenselement 720 is made of plastic material, and the object-side surface 721of the second lens element 720 has at least one inflection point.

The third lens element 730 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 731 in a paraxialregion thereof and an image-side surface being concave 732 in a paraxialregion thereof, which are both aspheric, the third lens element 730 ismade of plastic material, and both of the object-side surface 731 andthe image-side surface 732 of the third lens element 730 have at leastone inflection point.

The fourth lens element 740 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 741 in a paraxialregion thereof and an image-side surface being convex 742 in a paraxialregion thereof, which are both aspheric, the fourth lens element 740 ismade of plastic material, and the object-side surface 741 of the fourthlens element 740 has at least one inflection point.

The fifth lens element 750 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 751 in aparaxial region thereof and an image-side surface being convex 752 in aparaxial region thereof, which are both aspheric, the fifth lens element750 is made of plastic material, and both of the object-side surface 751and the image-side surface 752 of the fifth lens element 750 have atleast one inflection point.

The sixth lens element 760 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 761 in a paraxialregion thereof and an image-side surface being concave 762 in a paraxialregion thereof, which are both aspheric, the sixth lens element 760 ismade of plastic material, and both of the object-side surface 761 andthe image-side surface 762 of the sixth lens element 760 have at leastone inflection point.

The IR-cut filter 770 is made of glass and located between the sixthlens element 760 and the image surface 780, and will not affect thefocal length of the imaging optical system. The image sensor 790 isdisposed on or near the image surface 780 of the imaging optical system.

The detailed optical data of the 7th embodiment are shown in Table 13and the aspheric surface data are shown in Table 14 below.

TABLE 13 (Embodiment 7) f = 4.68 mm, Fno = 2.20, HFOV = 37.0 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Ape. Stop Plano −0.284 2 Lens 1 2.000 ASP0.738 Plastic 1.544 55.9 3.86 3 36.837 ASP 0.140 4 Lens 2 −31.746 ASP0.240 Plastic 1.640 23.3 −6.51 5 4.809 ASP 0.333 6 Lens 3 28.928 ASP0.495 Plastic 1.544 55.9 −38.48 7 12.073 ASP 0.146 8 Lens 4 4.229 ASP0.644 Plastic 1.544 55.9 6.82 9 −28.503 ASP 0.500 10 Lens 5 −1.187 ASP0.484 Plastic 1.544 55.9 −15.39 11 −1.582 ASP 0.052 12 Lens 6 1.325 ASP0.750 Plastic 1.535 55.7 36.98 13 1.140 ASP 0.700 14 IR-cut filter Plano0.200 Glass 1.517 64.2 — 15 Plano 0.601 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 14 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = −1.9730E−01 3.0000E+00 −3.0000E+01 −3.0000E+01 −3.0000E+01  3.0000E+00 A4 = 6.3571E−04 −4.0532E−02 −4.5120E−02  2.0030E−02 −3.7173E−02 −8.5224E−02A6 = −1.4676E−03  2.1186E−02  6.6740E−02  3.0872E−02 −2.8189E−02−4.2549E−03 A8 = −2.5802E−03 −2.2903E−02 −2.7739E−02 −9.8569E−04 4.6865E−02  4.5370E−03 A10 = −1.4041E−03  5.7760E−03 −1.6472E−02−2.5071E−02 −5.3475E−02 −2.1764E−03 A12 =  1.2142E−03 −1.2432E−03 2.2957E−02  2.3050E−02  2.3943E−02  3.1100E−03 A14 = −1.9570E−03−5.1327E−04 −6.5631E−03 −4.4402E−03 Surface # 8 9 10 11 12 13 k =−1.0230E+00 −1.0000E+00 −7.8961E+00 −6.1896E−01 −6.3599E+00 −3.8954E+00A4 = −6.9897E−02 −2.5438E−03 −7.4898E−02  2.4552E−02 −9.1022E−02−4.6369E−02 A6 = −1.2751E−02 −1.9929E−02 −2.2130E−03 −1.9238E−02 2.4757E−02  1.1186E−02 A8 = −3.7431E−03 −1.7930E−05  1.6766E−02 6.5577E−03 −1.1218E−02 −2.6734E−03 A10 =  1.5888E−04  2.2881E−03−4.1846E−03  1.4095E−03  3.8341E−03  4.6530E−04 A12 =  1.0670E−03−6.0729E−04 −1.0196E−05 −2.1251E−04 −6.9667E−04 −5.1885E−05 A14 = 1.4605E−03  3.5287E−05  9.0320E−05 −1.3304E−04  6.6076E−05  3.3063E−06A16 = −6.7243E−04 −4.4949E−06  2.0793E−05 −2.7209E−06 −9.0921E−08

In the 7th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 7th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 13 and Table 14as the following values and satisfy the following conditions:

7th Embodiment f [mm] 4.68 (R9 + R10)/(R9 − R10) −7.01 Fno 2.20 (f/f3) +(f/f4) 0.57 HFOV [deg.] 37.0 |f/f3| + |f/f4| + |f/f5| + |f/f6| 1.24CT3/CT2 2.06 Yc61/Yc62 0.61 T45/CT5 1.03 SD/TD 0.94 f/R8 −0.16 TL/ImgH1.67 f/R10 −2.96

8th Embodiment

FIG. 8A is a schematic view of an image capturing device according tothe 8th embodiment of the present disclosure. FIG. 8B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the8th embodiment.

In FIG. 8A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 890. The imaging optical system includes, in order from anobject side to an image side, a first lens element 810, an aperture stop800, a second lens element 820, a third lens element 830, a fourth lenselement 840, a fifth lens element 850, a sixth lens element 860, anIR-cut filter 870 and an image surface 880, wherein the imaging opticalsystem has a total of six lens elements (810-860) with refractive power,which are non-cemented lens element.

The first lens element 810 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 811 in a paraxialregion thereof and an image-side surface being concave 812 in a paraxialregion thereof, which are both aspheric, the first lens element 810 ismade of plastic material, and both of the object-side surface 811 andthe image-side surface 812 of the first lens element 810 have at leastone inflection point.

The second lens element 820 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 821 in a paraxialregion thereof and an image-side surface being concave 822 in a paraxialregion thereof, which are both aspheric, and the second lens element 820is made of plastic material.

The third lens element 830 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 831 in a paraxialregion thereof and an image-side surface being concave 832 in a paraxialregion thereof, which are both aspheric, the third lens element 830 ismade of plastic material, and both of the object-side surface 831 andthe image-side surface 832 of the third lens element 830 have at leastone inflection point.

The fourth lens element 840 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 841 in a paraxialregion thereof and an image-side surface being concave 842 in a paraxialregion thereof, which are both aspheric, the fourth lens element 840 ismade of plastic material, and both of the object-side surface 841 andthe image-side surface 842 of the fourth lens element 840 have at leastone inflection point.

The fifth lens element 850 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 851 in aparaxial region thereof and an image-side surface being convex 852 in aparaxial region thereof, which are both aspheric, the fifth lens element850 is made of plastic material, and the image-side surface 852 of thefifth lens element 850 has at least one inflection point.

The sixth lens element 860 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 861 in a paraxialregion thereof and an image-side surface being concave 862 in a paraxialregion thereof, which are both aspheric, the sixth lens element 860 ismade of plastic material, and both of the object-side surface 861 andthe image-side surface 862 of the sixth lens element 860 have at leastone inflection point.

The IR-cut filter 870 is made of glass and located between the sixthlens element 860 and the image surface 880, and will not affect thefocal length of the imaging optical system. The image sensor 890 isdisposed on or near the image surface 880 of the imaging optical system.

The detailed optical data of the 8th embodiment are shown in Table 15and the aspheric surface data are shown in Table 16 below.

TABLE 15 (Embodiment 8) f = 5.29 mm, Fno = 2.20, HFOV = 36.0 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.087 ASP 0.743 Plastic 1.535 55.7 4.612 11.903 ASP 0.097 3 Ape. Stop Plano −0.047 4 Lens 2 2.928 ASP 0.240Plastic 1.650 21.4 −8.31 5 1.837 ASP 0.342 6 Lens 3 4.144 ASP 0.379Plastic 1.544 55.9 33.26 7 5.202 ASP 0.611 8 Lens 4 16.443 ASP 0.329Plastic 1.544 55.9 35.87 9 103.606 ASP 0.300 10 Lens 5 −1.441 ASP 0.555Plastic 1.544 55.9 −52.21 11 −1.724 ASP 0.050 12 Lens 6 1.671 ASP 0.840Plastic 1.535 55.7 21.01 13 1.619 ASP 0.700 14 IR-cut filter Plano 0.230Glass 1.517 64.2 — 15 Plano 1.073 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 16 Aspheric Coefficients Surface # 1 2 4 5 6 7 k = −5.2837E−02−9.4668E−01 −1.5122E+00 −3.6300E+00  −2.6033E+01 −9.0029E−01 A4 = 2.8041E−03 −2.3222E−02 −6.8809E−02 5.6129E−03  1.5770E−02 −3.3707E−02A6 = −6.6677E−04  1.6633E−02  3.1710E−02 4.3967E−03 −2.0481E−02 3.5016E−03 A8 = −2.4322E−04 −1.3221E−02 −8.0359E−03 6.4871E−03 9.4949E−03  5.7737E−04 A10 = −2.0312E−04  5.2374E−03 −3.8994E−03−3.2787E−03  −5.8495E−03 −4.3598E−03 A12 =  4.8687E−05 −5.7527E−04 7.2594E−03 2.0834E−03  2.5421E−03  2.7293E−03 A14 = −1.1089E−04−1.4940E−04 −2.2801E−03 −2.5135E−05  Surface # 8 9 10 11 12 13 k =−5.2362E+00 −1.0000E+00 −9.0208E+00 −7.1677E−01  −7.1978E+00 −4.7664E+00A4 = −7.7652E−02 −2.3664E−02 −1.6899E−02 1.4495E−02 −6.1583E−02−3.7575E−02 A6 = −1.2980E−02 −2.7795E−02  2.6009E−03 −6.2902E−03  1.5541E−02  6.9135E−03 A8 = −9.1439E−03  6.2559E−03  5.3780E−033.2647E−03 −5.0315E−03 −1.2797E−03 A10 =  1.0824E−03  1.0674E−03−2.0378E−03 4.2474E−04  1.3597E−03  1.6848E−04 A12 =  1.9955E−03−3.3480E−04 −3.9073E−05 −9.1349E−05  −2.0268E−04 −1.4686E−05 A14 = 7.8069E−04 −2.8716E−05  3.1019E−05 −3.4603E−05   1.5114E−05  7.4470E−07A16 = −3.9539E−04  4.1488E−06 4.7956E−06 −4.4886E−07 −1.6293E−08

In the 8th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 8th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 15 and Table 16as the following values and satisfy the following conditions:

8th Embodiment f [mm] 5.29 (R9 + R10)/(R9 − R10) −11.18 Fno 2.20(f/f3) + (f/f4) 0.31 HFOV [deg.] 36.0 |f/f3| + |f/f4| + |f/f5| + |f/f6|0.66 CT3/CT2 1.58 Yc61/Yc62 0.75 T45/CT5 0.54 SD/TD 0.81 f/R8 0.05TL/ImgH 1.61 f/R10 −3.07

9th Embodiment

FIG. 9A is a schematic view of an image capturing device according tothe 9th embodiment of the present disclosure. FIG. 9B shows, in orderfrom left to right, spherical aberration curves, astigmatic field curvesand a distortion curve of the image capturing device according to the9th embodiment.

In FIG. 9A, the image capturing device includes the imaging opticalsystem (not otherwise herein labeled) of the present disclosure and animage sensor 990. The imaging optical system includes, in order from anobject side to an image side, an aperture stop 900, a first lens element910, a second lens element 920, a third lens element 930, a fourth lenselement 940, a fifth lens element 950, a sixth lens element 960, anIR-cut filter 970 and an image surface 980, wherein the imaging opticalsystem has a total of six lens elements (910-960) with refractive power,which are non-cemented lens element.

The first lens element 910 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 911 in a paraxialregion thereof and an image-side surface being convex 912 in a paraxialregion thereof, which are both aspheric, the first lens element 910 ismade of glass material, and both of the object-side surface 911 and theimage-side surface 912 of the first lens element 910 have at least oneinflection point.

The second lens element 920 with negative refractive power in a paraxialregion thereof has an object-side surface being convex 921 in a paraxialregion thereof and an image-side surface being concave 922 in a paraxialregion thereof, which are both aspheric, and the second lens element 920is made of plastic material.

The third lens element 930 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 931 in a paraxialregion thereof and an image-side surface being convex 932 in a paraxialregion thereof, which are both aspheric, the third lens element 930 ismade of plastic material, and both of the object-side surface 931 andthe image-side surface 932 of the third lens element 930 have at leastone inflection point.

The fourth lens element 940 with negative refractive power in a paraxialregion thereof has an object-side surface being concave 941 in aparaxial region thereof and an image-side surface being concave 942 in aparaxial region thereof, which are both aspheric, the fourth lenselement 940 is made of plastic material, and both of the object-sidesurface 941 and the image-side surface 942 of the fourth lens element940 have at least one inflection point.

The fifth lens element 950 with positive refractive power in a paraxialregion thereof has an object-side surface being concave 951 in aparaxial region thereof and an image-side surface being convex 952 in aparaxial region thereof, which are both aspheric, the fifth lens element950 is made of plastic material, and the image-side surface 952 of thefifth lens element 950 has at least one inflection point.

The sixth lens element 960 with positive refractive power in a paraxialregion thereof has an object-side surface being convex 961 in a paraxialregion thereof and an image-side surface being concave 962 in a paraxialregion thereof, which are both aspheric, the sixth lens element 960 ismade of plastic material, and both of the object-side surface 961 andthe image-side surface 962 of the sixth lens element 960 have at leastone inflection point.

The IR-cut filter 970 is made of glass and located between the sixthlens element 960 and the image surface 980, and will not affect thefocal length of the imaging optical system. The image sensor 990 isdisposed on or near the image surface 980 of the imaging optical system.

The detailed optical data of the 9th embodiment are shown in Table 17and the aspheric surface data are shown in Table 18 below.

TABLE 17 (Embodiment 9) f = 4.56 mm, Fno = 2.20, HFOV = 40.7 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Ape. Stop Plano −0.270 2 Lens 1 2.183 ASP0.487 Glass 1.603 38.0 3.50 3 −60.896 ASP 0.090 4 Lens 2 12.010 ASP0.240 Plastic 1.639 23.5 −3.81 5 2.009 ASP 0.230 6 Lens 3 3.939 ASP0.552 Plastic 1.530 55.8 7.33 7 −281.259 ASP 0.536 8 Lens 4 −298.010 ASP0.217 Plastic 1.639 23.5 −42.29 9 29.726 ASP 0.409 10 Lens 5 −1.418 ASP0.435 Plastic 1.535 55.7 36.73 11 −1.464 ASP 0.050 12 Lens 6 1.371 ASP0.761 Plastic 1.535 55.7 25.41 13 1.229 ASP 0.672 14 IR-cut filter Plano0.230 Glass 1.517 64.2 — 15 Plano 0.948 16 Image Plano — Note: Referencewavelength is 587.6 nm (d-line).

TABLE 18 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = 2.0880E−01−3.0000E+01  3.0000E+00 −7.7625E+00  −1.4060E+01  3.0000E+00 A4 =5.4657E−03  4.7005E−02 −4.2111E−02 1.9048E−02  1.2645E−02 −1.9573E−02 A6= 4.3437E−03 −3.2727E−02  3.0003E−02 6.2526E−03 −1.4595E−02 −5.3597E−03A8 = −4.4485E−03   1.0472E−02 −1.8091E−02 2.5840E−03  5.0951E−03−4.7129E−03 A10 = 4.1010E−03  1.2961E−02  3.6563E−03 −4.0646E−04 −5.6803E−03 −2.6812E−03 A12 = 4.0524E−03 −5.2942E−03  5.0342E−03−4.8408E−03   1.3742E−03  9.6133E−04 A14 = −3.1892E−03  −6.4360E−03−8.8982E−03 2.6125E−03 Surface # 8 9 10 11 12 13 k = 3.0000E+00−1.0000E+00 −1.2630E+01 −8.0436E−01  −7.6731E+00 −4.3849E+00 A4 =−1.4385E−01  −1.2339E−01 −7.2305E−02 5.9591E−03 −6.3000E−02 −4.2085E−02A6 = 1.0448E−02 −3.1730E−03  5.4311E−03 4.9476E−03  1.5438E−02 8.4900E−03 A8 = −4.1711E−03   1.0595E−02  1.2777E−02 3.4747E−03−4.9922E−03 −1.5201E−03 A10 = 2.1783E−03  1.0254E−03 −2.1395E−032.1862E−04  1.3639E−03  1.8489E−04 A12 = 2.3488E−03 −2.8302E−04−7.6460E−04 −1.6143E−04  −2.0326E−04 −1.4985E−05 A14 = 1.1832E−03−1.8758E−05 −1.5578E−04 −4.3444E−05   1.5025E−05  6.9267E−07 A16 =−7.3930E−04   6.2416E−05 7.0902E−06 −4.3907E−07 −1.2696E−08

In the 9th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in thefollowing table are the same as those stated in the 1st embodiment withcorresponding values for the 9th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from Table 17 and Table 18as the following values and satisfy the following conditions:

9th Embodiment f [mm] 4.56 (R9 + R10)/(R9 − R10) −62.74 Fno 2.20(f/f3) + (f/f4) 0.51 HFOV [deg.] 40.7 |f/f3| + |f/f4| + |f/f5| + |f/f6|1.03 CT3/CT2 2.30 Yc61/Yc62 0.72 T45/CT5 0.94 SD/TD 0.93 f/R8 0.15TL/ImgH 1.43 f/R10 −3.11

The foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. It is to be noted thatTABLES 1-18 show different data of the different embodiments; however,the data of the different embodiments are obtained from experiments. Theembodiments were chosen and described in order to best explain theprinciples of the disclosure and its practical applications, to therebyenable others skilled in the art to best utilize the disclosure andvarious embodiments with various modifications as are suited to theparticular use contemplated. The embodiments depicted above and theappended drawings are exemplary and are not intended to be exhaustive orto limit the scope of the present disclosure to the precise formsdisclosed. Many modifications and variations are possible in view of theabove teachings.

What is claimed is:
 1. An imaging optical system, comprising six lenselements, the six lens elements being, in order from an object side toan image side: a first lens element, a second lens element, a third lenselement, a fourth lens element, a fifth lens element, and a sixth lenselement; wherein the second lens element has negative refractive powerin a paraxial region thereof, the third lens element has an image-sidesurface being concave in a paraxial region thereof, the fourth lenselement has at least one inflection point, and the sixth lens elementwith positive refractive power in a paraxial region thereof has anobject-side surface and an image-side surface being aspheric; wherein anaxial distance between the fourth lens element and the fifth lenselement is a maximum among axial distances of every two adjacent lenselements of the imaging optical system, and a central thickness of thefirst lens element is larger than a central thickness of the sixth lenselement; wherein the imaging optical system further comprises anaperture stop, an axial distance between the aperture stop and theimage-side surface of the sixth lens element is SD, an axial distancebetween an object-side surface of the first lens element and theimage-side surface of the sixth lens element is TD, and the followingcondition is satisfied:0.75<SD/TD<1.1.
 2. The image optical system of claim 1, wherein thefirst lens element has positive refractive power in a paraxial regionthereof and the object-side surface of the first lens element is convexin the paraxial region thereof.
 3. The imaging optical system of claim1, wherein the first lens element has an image-side surface beingconcave in a paraxial region thereof.
 4. The imaging optical system ofclaim 1, wherein the second lens element has an object-side surfacebeing convex in a paraxial region thereof.
 5. The imaging optical systemof claim 1, wherein the third lens element has negative refractive powerin a paraxial region thereof.
 6. The imaging optical system of claim 1,wherein the fourth lens element has an image-side surface being convexin a paraxial region thereof.
 7. The imaging optical system of claim 1,wherein the fifth lens element has negative refractive power in aparaxial region thereof.
 8. The imaging optical system of claim 1,wherein the object-side surface of the sixth lens element is convex in aparaxial region thereof.
 9. The imaging optical system of claim 1,wherein the image-side surface of the sixth lens element is concave in aparaxial region thereof and has at least one inflection point.
 10. Theimaging optical system of claim 1, wherein an f-number of the imagingoptical system is Fno, and the following condition is satisfied:1.50<Fno<2.50.
 11. The imaging optical system of claim 1, wherein eachof the six lens elements is a singlet and not cemented to each other, avertical distance between a non-axial critical point on the object-sidesurface of the sixth lens element and an optical axis is Yc61, avertical distance between a non-axial critical point on the image-sidesurface of the sixth lens element and the optical axis is Yc62, and thefollowing condition is satisfied:0.2<Yc61/Yc62<0.9.
 12. An imaging optical system, comprising six lenselements, the six lens elements being, in order from an object side toan image side: a first lens element, a second lens element, a third lenselement, a fourth lens element, a fifth lens element, and a sixth lenselement; wherein the first lens element has positive refractive power ina paraxial region thereof, the fourth lens element has negativerefractive power in a paraxial region thereof and at least oneinflection point, and the sixth lens element with positive refractivepower in a paraxial region thereof has an object-side surface and animage-side surface being aspheric; wherein an axial distance between thefourth lens element and the fifth lens element is a maximum among axialdistances of every two adjacent lens elements of the imaging opticalsystem wherein the imaging optical system further comprises an aperturestop, an axial distance between the aperture stop and the image-sidesurface of the sixth lens element is SD, an axial distance between anobject-side surface of the first lens element and the image-side surfaceof the sixth lens element is TD, and the following condition issatisfied:0.75<SD/TD<1.1.
 13. The imaging optical system of claim 12, wherein thefirst lens element has an image-side surface being concave in a paraxialregion thereof.
 14. The imaging optical system of claim 12, wherein thesecond lens element has an object-side surface being convex in aparaxial region thereof.
 15. The imaging optical system of claim 12,wherein each of the first lens element, the second lens element, thethird lens element, and the fourth lens element has both of anobject-side surface and an image-side surface being aspheric, and thesecond lens element has negative refractive power in a paraxial regionthereof.
 16. The imaging optical system of claim 12, wherein theobject-side surface of the sixth lens element is convex in a paraxialregion thereof.
 17. The imaging optical system of claim 12, wherein theimage-side surface of the sixth lens element is concave in a paraxialregion thereof.
 18. The imaging optical system of claim 12, wherein afocal length of the imaging optical system is f, a curvature radius ofan image-side surface of the fourth lens element is R8, the followingcondition is satisfied:0<f/R8.
 19. The imaging optical system of claim 12, wherein each of thesix lens elements is a singlet and not cemented to each other and theaperture stop is disposed between an imaged object and the second lenselement.
 20. The imaging optical system of claim 12, wherein at leastfive surfaces of the object-side surfaces and the image-side surfaces ofthe six lens elements have at least one inflection point on each of theat least five surfaces.
 21. The imaging optical system of claim 12,wherein a focal length of the imaging optical system is f, a focallength of the third lens element is f3, a focal length of the fourthlens element is f4, a focal length of the fifth lens element is f5, afocal length of the sixth lens element is f6, and the followingcondition is satisfied:0.6<|f/f3|+|f/f4|+|f/f5|+|f/f6|<1.7.
 22. The imaging optical system ofclaim 12, wherein the sign of both of a curvature radius of anobject-side surface and a curvature radius of an image-side surface ofthe fourth lens element are the same.
 23. An image capturing device,comprising: the imaging optical system of claim 12; and an image sensor.24. An electronic device, comprising: the image capturing device ofclaim
 23. 25. An imaging optical system, comprising six lens elements,the six lens elements being, in order from an object side to an imageside: a first lens element, a second lens element, a third lens element,a fourth lens element, a fifth lens element, and a sixth lens element;wherein the first lens element has positive refractive power in aparaxial region, the second lens element has an object-side surfacebeing convex in a paraxial region thereof, the fourth lens element hasat least one inflection point, and the sixth lens element with positiverefractive power in a paraxial region thereof has an object-side surfaceand an image-side surface being aspheric; wherein an axial distancebetween the fourth lens element and the fifth lens element is a maximumamong axial distances of every two adjacent lens elements of the imagingoptical system, and a central thickness of the first lens element islarger than a central thickness of the sixth lens element.
 26. Theimaging optical system of claim 25, wherein the third lens element hasnegative refractive power in a paraxial region thereof, and each of thesix lens elements is a singlet and not cemented to each other.
 27. Theimaging optical system of claim 25, wherein each of the first lenselement, the second lens element, the third lens element, and the fourthlens element has both of an object-side surface and an image-sidesurface being aspheric, and the image-side surface of the fourth lenselement is convex in a paraxial region thereof.
 28. The imaging opticalsystem of claim 25, wherein the image-side surface of the sixth lenselement is concave in a paraxial region thereof and has at least oneinflection point.
 29. The imaging optical system of claim 25, whereinthe object-side surface of the sixth lens element is convex in aparaxial region thereof.
 30. The imaging optical system of claim 25,wherein at least five surfaces of the object-side surfaces and theimage-side surfaces of the six lens elements have has at least oneinflection point on each of the at least five surfaces.
 31. The imagingoptical system of claim 25, wherein an f-number of the imaging opticalsystem is Fno, and the following condition is satisfied:1.50<Fno<2.50.
 32. The imaging optical system of claim 25, wherein afocal length of the imaging optical system is f, a curvature radius ofan image-side surface of the fourth lens element is R8, the followingcondition is satisfied:−0.50<f/R8.
 33. The imaging optical system of claim 25, wherein acentral thickness of the third lens element is CT3, a central thicknessof the second lens element is CT2, the following condition is satisfied:1.40<CT3/CT2.
 34. The imaging optical system of claim 25, wherein acurvature radius of an object-side surface of the fifth lens element isR9, a curvature radius of an image-side surface of the fifth lenselement is R10, and the following condition is satisfied:(R9+R10)/(R9−R10)<2.0.
 35. An imaging optical system, comprising sixlens elements, the six lens elements being, in order from an object sideto an image side: a first lens element, a second lens element, a thirdlens element, a fourth lens element, a fifth lens element, and a sixthlens element; wherein the fourth lens element has at least oneinflection point and the sixth lens element has positive refractivepower in a paraxial region thereof; wherein an axial distance betweenthe fourth lens element and the fifth lens element is a maximum amongaxial distances of every two adjacent lens elements of the imagingoptical system, and a central thickness of the first lens element islarger than a central thickness of the sixth lens element; wherein afocal length of the imaging optical system is f, a curvature radius ofan image-side surface of the fourth lens element is R8, and the imagingoptical system further comprises an aperture stop, an axial distancebetween the aperture stop and the image-side surface of the sixth lenselement is SD, an axial distance between an object-side surface of thefirst lens element and the image-side surface of the sixth lens elementis TD, and the following conditions are satisfied:−0.50<f/R8, and0.75<SD/TD<1.1.
 36. The imaging optical system of claim 35, wherein thefourth lens element has an object-side surface being convex in aparaxial region thereof.
 37. The imaging optical system of claim 35,wherein the fifth lens element has an object-side surface being concavein a paraxial region thereof.
 38. The imaging optical system of claim35, wherein the third lens element has negative refractive power in aparaxial region thereof.